Connectors can be mounted to circuit boards, with the tail ends of the contacts soldered to plated-through holes of the circuit board, and with the mating forward ends of the contacts lying in insulative layers of the connector housing. One fabrication method includes projecting the forward contact ends into the insulative layers, projecting the tail ends of the contacts into the circuit board and with the front of the board abutting the connector housing, and then soldering the tail ends to the circuit board as by vapor phase reflow. Such a technique does not allow for visual inspection of the soldered joints, especially on inner rows of contacts, or removal of solder flux that may be trapped between board and insulator. In connectors with higher contact densities, there is an increased susceptibility to solder bridging between adjacent contacts, so visual inspection is highly desirable. It would be possible to insert just the contacts into the circuit board and solder them in place, inspect and deflux the joints, and then insert the front contact ends into the connector housing. However, the front ends of the contacts then may not be accurately aligned with the holes in the insulative layer. This can lead to great difficulty in inserting the contacts into the insulative layers or can lead to breaking of the solder joints during such installation. A connector assembly and method for fabricating it, which enabled visual inspection of solder joints of the contacts with the circuit board and facilitated removal of solder flux, while assuring that the contacts were in alignment with holes in the connector housing during the solder process, would facilitate assembly.
When a plug and socket contact are mated, it is generally desirable to provide a vapor-tight seal around the mating contact portions. This is often accomplished by providing the socket connector with a soft rubber layer that is compressed against a more rigid layer on the plug connector. There is often a wide area of contact, so that for a given mating force there is only a small compression of the rubber. It would be desirable if there were a maximum of rubber compression at the seal, and it occurred immediately around the mating contact locations, so sealing would be assured throughout a range of depths of insertion of one connector into the other and with only a small increase in connector mating force.